Crimping tool



Dec.` 4, 1956 K. L. NEIJSTROM ET AL CRIMPING TOOL Filed March 24, 1954-INVENTORS KENNETH L. Ns/J'JTROM KENNETH E. PETERsoN WILLIAM 5J "wirUnited States Patent O CRIMPING TOOL Kenneth L. Neijstrom,5 Camp Hill,Kenneth E. Peterson,

New Cumberland,.and. William-R. Evans, Oberlin, Pa., assignors toAircraft-Marinev Prducts,. Inc., Hams-.-

This inventionrelates. primarily'to. the. field. of portablehand-operatedtoolsfor crimping electrical connectors or terminals ontowire conductors.

of wires are unavailable or atl a. distance. a crimping tool embodyingthe invention may be quickly latched. around a. wire, from onev side ofthe wire with the crimping dies held firmly andy accurately in`alignmentwith. each other.

When the headislatched, it firmly-engages'. and-.locks itself into arigidly closed positionzfromfwhichy it cannot.

accidentally becomeV disengaged, prior. to theclosure of the dies.against thev wire. Moreover, the head'. may be readily unlatched. and.automatically swingsI to. full open position by operationrofy asinglelatch.l member.

The present. invention is described as embodied ina.

for repair work and. for installation of. new equipment' and assemblywork. In working on existing roverhead or. underground: lines and inmany other situationsthere are places where the standing part of theconductory is accessible only from. one side with no ends available overwhich to slide the tool head. Often the space behind the wire islimited. becausel ofnearby structures, so that it is extremely awkward.:or even impossible to. make4 a satisfactory connection with thetoolsavailable today. Wheresucha connection can be made with present tools,it often is .unduly fatiguing to` the operator. The head of. a crimpingtool, according to the present invention can be readily ysnapped aroundthestanding par-t of a wire. with the dies automatically aligned andpositionedftofacilitate the making, of a high quality connection withoutundue strain onthe operator.

In work on large. size wires and cables underk service conditions theconnectionsare required tohave a1 high mechanical strength anda.large'current-carryingcapacity. Thus, during the crimping operation, toinsure a high quality connection, the. dies must be susceptible: to fullcloseure relatively easily regardless of the limited. space aroundthewire or the angle from which the wire must be approached. Anadvantage of the present invention is-that the diesarealwaysaccuratelylv positionedl and susceptible to fullaccuratelyalignedclosure.

Among the advantages of: the present. invention is the fact, that. itsimplies quick removal of the dies and'. easy replacement by different,sizes or types of dies. Thus, a single tool may be used for severaldifferent sizes of wire and for. making different types of connections.Moreover,.,a.single-tool together with a set of dies isrelatively lightin weight. so that a lineman can carry them up, a pole or into a manholeand work oni various sizes of cables and make different connections, al1with the one tool and set of dies.

The invention has par-- ticular utilityA for making connections orrepairs in existe4 ing wire installations-and in applications whereythe. ends` The head, ofI

They operation off the hydraulic mechanismice With the latcharrangements disclosed, the dies are positively held in accuraterelation to' each other, and the increase of pressure during thecrimping operation serves to lock the tool head moreA tightly in correctorientation with respect tothe wire orconnector being crimped.

Another advantage is that thev die; assemblies are: sup ported so as torequire only a small clearance between the portion of the wire on which.the work is being per'- formed and any nearby structures, for: example,suchy as the wall of' a manholeor4 a roof truss along which the.

wire is strung. Thus, ini many cases it: isr unnecessary to pry the wireaway from the obstruction or. to approachy it from an awkward position.

it is an object of. thel present invention toA provide.. a handycrimping tool capable of producing-thehigh crimping pressures necessaryfory work on intermediatel and' large size conductorsv tovproduce.connections. having a.

high mechanical strength and a high electrical performance, and yet onewhich can be readilyused in crampedl locations and where only smallclearances are available around the conductor. beingcrimped.

The various aspects, objects,` and advantages of the present inventionwill` be. in partpointed `out ancln in part apparent, fromv the.following description taken in-` conjunctionwith the accompanying,drawings, in which:

Figure 1 isa, perspective view of a hydraulically-operated hand toolembodyingfthe present invention;

Figure 2 is aperspective view of: artype ofconnection such. as` can bemade by the present invention;

Figure 3 isa. s'ideview, enlarged andrpartially in section, of the, headportion of the toolshown inFigure. 1;

Figure 4 is a side View similar to Figure 3 but with.

the. head. shown ini fullyy open. position;

Figure 5 isa. top viewy of thevhead, shown in Figures 3y and 4,partially in section;

Figure 6 is a. View of portions of the latch andy arm of the tool headofI Figure 5, further enlarged to show in. detail. the, form. of, theS-curved` engageable latchi'ng surfaces thereof; and..

Figure` 7 showsthese surfacescorrespondingly enlarged andinlatchedengagement with. each other.

The type of tool shownin Figure 1 is adapted t-omake connections of thetype formedby telescoping a sleeve or ferrule portion ofy a connectorover a bare portion of a wire, and then. crimping` the connector intov afirm mechanical. and. electr-ical bond with the wire. Inv this crimpingoperation. both? the connector and conductor are placed within they headof the' tool, while'it is in the unlatched position, the headis latched,andthe connection is made by applying a large force to the die pieces,thus crimping the walls of the.. sleeve inwardly against the-conductor,-to make a. connectionA such as that. shown in Figure 2,.for example.v n

The tool, as seen inFigure 1, includesa head portion 10, a body portion12, a xed handle 1.4 and a movable. handle lhingedfto the body by a.pivot` 18.' Duringa crimping operation. the two handles are movedtowardv one another. in av series. of. short pumping strokes causing alarge hydraulic force to be built up Within-the body 12 so thata movabledie 20 (see- Figure 3) carried by a hydraulically driven ram21. isforced toward a` lixed die 22 held ina member 2.4.extending across thehead of the tool. This member 24A advantageously is hinged to enable itto beswungopen, for reasons discussed below, but during`crimpingoperation is latched squarely across the path of. movable. die20. so as to` hold die surfaces of the fixed die 22 accurately alignedwith respect to the path ofthe die surfaces ofmovable die 2.0.

The member. 24 has.` aV straight intermediate portion- 25 on.which` die22 isheld and has aside arm 26 with a pair of hinger plates` 28 on its.butt end. These plates 28 are hingedby a pivot bolt 30 to three hingeplates 31, 32, and

33 fixed to one side of the tool head laterally displaced from the pathof movable die 20 and arranged so that member 24 can swing out throughapproximately a 90 angle to a Wide open position, as seen in full linesin Figure 4.

It should be noted that side arm 26 is connected to the intermediateportion of member 24 by a 90 elbow 34 and that, when member 24 islatched closed, this intermediate portion presents an inner diesupporting surface extending perpendicularly across the path of die 20.Thus, with member 24 in closed position the fixed die 22 is held by thisperpendicular surface squarely and accurately in alignment with movabledie 20, while side arm 26 extends out from the frame of the tool headparallel to the direction of the thrust of ram 21 to anchor its side ofthe intermediate portion of member 24 firmly in place against thisthrust.

As shown in Figure 3, hinged member 24 is held in closed position bymeans of a latch 36 having an S-curved overhanging nose surface 38 onits inner face near its free end, which engages a mating S-curved lipsurface 40 on the free end of member 24 opposite to elbow 34. In latchedposition, latch 36 also extends out from the frame of the tool headparallel to the path of die 22 to anchor its side of the intermediateportion of member 24 iirmly in place against the thrust of ram 21.

The butt end of latch 36 is hingedly secured to the head of the tool bya pair of hinge plates 41 held by a pivot bolt 42 in engagement withthree hinge plates 43, 44 and 45 which are fixed to the opposite side ofthe path of die 20 from the hinge 30 of member 24. Member 24 and latch36 can be removed by unscrewing their respective pivot bolts 30 and 42which have screw driver slots in one end and their other ends threadedand screwed into the tiXed outside hinge plates 31 and 43, respectively.

In order to bias the latch 36 inwardly in the direction of the arrow 46(Figure 3) toward latching position, a pair of small compression springs48 (see also Figure 5) are set in suitable recesses in the head betweenthe hinge plates 43 and 44, and 44 and 45, respectively. The outer halfof the butt end of the latch is chamfered at S to provide a stop so thatthe latch cannot be swung open farther than necessary for easyoperation, i. e., to the dotted line position 52 shown in Figure 4. Tofacilitate in unlatching the latch and swinging it into open position, athumb tab 54 is provided on its free end.

Member 24 is biased outwardly in the direction of the arrow 56 towardits open position, by means of a hinge spring 58 which fits into a slotin the center hinge plate 32. This spring passes around the pivot bolt30, and is held in concentric position on the pivot bolt by a spacerwasher 60. The ends of the spring are inserted into hole 62 in thebottom of this slot and another hole 64 in the butt end of the side arm26 between hinge plates 28. When member 24 is released it automaticallyswings outwardly approximately 90 away from thel path of the movable dieinto its full open position, shown by the solid lines in Figure 4.

As mentioned above, among the advantages of the present invention arethose provided because the dies can be latched in place around a wirewhich is already installed. This latching may be readily accomplished inspite of the fact that 'the wire may have only a slight clearance behindit. In its open position member 24 can readily be inserted behind astanding wire even if it is spaced only a short distance away from anobstructing surface such as the wall of a manhole. This is accomplishedby inserting the free end of member 24 from one side so that it projectsbehind the wire with die 22 adjacent the Wire. Then the handles 14 and16 are swung out away from the wall, and the head is latched with thehandles projecting out at right angles to this obstructing surface, thusgiving the operator maximum working room.

When latching member 24 `into closed position, the

operation takes place as follows: the latch 36 is allowed to occupy itsreleased inner position, shown in full-lines in Figure 3. The operatorthen merely swings member 24 in toward closed position against thetorque of the spring 58. As the inner corner of the lip surface 40 onthe free end of member 24 (see dotted line position in Figure 3) strikesagainst the surface 38 on the latch 36, the latch is thereby pushedpartially open to the dottedline position shown in Figure 3, whereby thetip 68 of lip 40 is enabled to clear the tip 70 of the nose 38 and lip40 moves into the recess 71 below the nose. The latch 36 thenimmediately swings back to its former position, so that when member 24is released, it swings outwardly only a short distance to the full lineposition shown in Figure 3. In this position the two S-curved surfaces38 and 44) are fully engaged as shown enlarged in Figure 7. Theintermediate portion of member 24 is then held in fixed position by theside member 26 and by the latch 36 with the die 22 squarely across theline of the path of the impression die 20. Member 24 cannot accidentallydisplace itself prior to the application of the crimping force to thewire because the latch springs 48 continuously urge the latch towardengaged position while the spring 58 continuously urges member 24towards engaged position.

In unlatching the arm 24, the operator merely presses on the thumb tab54 moving latch 36 a slight ways outwardly and the S-curved surface 38cams the free end of member 24 inwardly a small distance to free it toswing out into fully open position.

Among the advantages of this arrangement are those that result from thefact that the member 24 and its latch 36 are biased Iso that when thetool head is closed, the hook surfaces are fully engaged and heldengaged under spring pressure so that member 24 is already in its finalcrimping position even before any crimping pressure is applied to thework. This means that as the crimping force is applied, the S-curvedsurfaces merely becomes more lirmly engaged but there is no motion ofthe die 22. Also, following a crimping operation, the operator, caninstantly release the dies merely by pulling outwardly on the thumb tab54.

Another advantage of this arrangement is that the latch 36 is secured tothe head of the tool by a hinge structure which is substantially thesame as the hinge structure for the side member 26 `of member 24. Thus,under the tremendous forces developed during the crimping operation,both hinges act the same and hold the die 22 in accurate alignmentopposite the impression die 20 in spite of any slight elasticdeformation of the metal of the tool head due to the tremendous crimpingforces involved.

The die 22 is supported on an inner die-supporting surface 72 of themember 24 which is a ground surface accurately spaced from the opposingdie-supporting surface 74 of the ram 21. Because of the accuracy ofspacing of these two die-supporting surfaces, the amount of crimpingobtained with different sets of dies may be regulated by thepredetermined spacing of the die face and seating surfaces of the diesthemselves rather than by making changes in the tool head itself.

It will be seen that since member 24, when released, automaticallyswings to the fully open position, it is convenient to remove andreplace the dies 20 and 22. The die 22 is held by its stem 76 in a hole78 in the intermediate portion of member 24 by means of a springbiasedball detent and its base rests against the inner die-supporting surface72. v Similarly, the die piece 20 is held against the surface 74 by aball detent (seen in Fig. 3) which engages its die stern projecting intoa recess in the ram 21.

In Figures 6 and 7 are shown in detail the forms of the S-curvedsurfaces 38 and 40. In order to provide a strong holding action, each ofthese S-curved surfaces has a central inclined portion L 82, which isplanar and which is tangent on each side to a cylindrical curve, eachtheseV curves has a larger radius R'i and the other has asmaller radiusR2, the outerv curves forming-the tips`- 681 and 70 of the lip 40 andnose 38, respectively. Thus, when these two surfaces-are engaged, asshowrr in Figure 7, the engagement takes place. onlyy along the planarsurfaces 82, and in each case the tipis clear of; its associated hollow.Thus, any grit whicht may accidentally have become lodged in thesehollows is. cleared so that it will not affect the accuracy oftheposition of member. 24 with respect to the latch 36. This accuracy isimportant, for it assures the correct positioning of member 24 withrespect to the rest of the head of the tool during crimping and hencethe correct positioning of the fixed die 22. Thus, the movable die 20 isenabled always to approach the fixed die the predetermined desired:optimum amount to produce the best crimping action for the particularset Iof dies used. It assures that the inner die-supporting surface 72-of member 24 is always perpendicular to the path of the die 20.

The angle of slope of the inclined planar surfaces 82 may be in theapproximate range from to 45 with respect to the perpendicular to thepath of die 20. The outer radii R1 may be in the approximate range from.05 to .20 inch, and the inner radii R2 in the approximate range from.03 to .15 inches, with R1 being from about 1.1 to `about 1.5 times R2.In a particular successful tool head the inclined planar surface 82 wasat an angle` of 30 and the radius R1 was approximately 1.35 times theradius R2, these radii being .062 and .046 inch, respectively.

With this embodiment shown, the two pivots 30 and 42 are positionedlaterally with respect to the center line of the path of the movable die20, and they are spaced therefrom an equal distance on opposite sides ofit. Also,

it should be noted that both of these pivots are positioned away fromthe plane of the die-supporting surface 72 of member 24 a significantdistance in the direction of the die 20, whereby the movable die 20 asit is driven by ram 21 toward its fully crimped position, shown inFigure 3, passes to a piosition intermediate these pivots with themember and latch being relatively unencumbered and projecting out awayfrom the pivots to an easily accessible position.

Moreover, with this arrangement, the free end of member 24 can be easilyslipped between an obstruction and the wire to be crimped with nointerference from the latch 36. The only space required between anobstruction and the Wire is the thickness of member 24 plus the depth ofthe fixed die 22.

It is thus seen that we have provided a tool for crimping connectors andterminals that is well adapted to attain the ends and objectshereinbefore set forth, and which is subject to `a variety ofmodifications -so that it may be best fitted for a particular use. It isto be understood that the description and drawings are for the purposeof illustrating the invention in accordance with the statutoryrequirements.

We claim: l. In a tool for crimping connectors onto wire wherein a firstdie is supported in the head of the tool during a crimping operation anda second die in the tool is driven along a path of operation toward saidfirst die, apparatus enabling said dies to be latched into position onopposite sides of the work to be crimped with said dies maintainedaccurately aligned during the crimping operation comprising a hinged topmember for supporting said first die, a first hinge connecting one sideof said top member in the head of the tool, said first hinge beingspaced laterally to one side of said die path a predetermined distanceand enabling said hinged top member to be swung between a closedposition in which said first die is in aligned position in said pathahead of said second die, and an open position in which said first dieis removed from said path, a

laterally to the other side of 'saidl path from said' firstv hinge' andspaced'the same-predetermined distance from said path as said firsthinge, said second hinge enabling said latchtobe swung between alatching position and-an unlatchingA position, tirst spring meanscoupled betweenV said member andsaid tool head and urging said member toswing from its closed towards-its open position, second springy meanscoupled between said latch and said toolv head and urging said latchtoward'its latching position, saidhingedtop member having onthe-opposite side from itsfhi'nge a lip witha convex rounded surface anda first recess adjacent thereto with a concave rounded surface, and afirst straight surface therebetween tangent to both of said roundedsurfaces, said latch having thereon spaced from its hinge a nose with aconvex rounded surface and a second recess adjacent thereto with aconcave rounded surface, and a second straight surface therebetweentangent to both of said rounded surfaces of said nose and second recess,both of said convex surfaces having a larger effective radius than saidconcave surfaces and both of said straight surfaces being equallyinclined with respect to said path and in engagement with each otherwhen said apparatus is latched in closed position.

2. In a tool for crimping electrical conductors, of the ty-pe having adie member movable on the tool body toward a die element supported onthe tool head, the improvement whereby said die element can be latchedin a closed position and is automatically latched and locked inpredetermined position on the tool head opposite said die member when itis closed and automatically swings into the fully open position whenunlatched, said improvement comprising: a unitary die element supporthaving an L- shape as seen in elevation including a top portion adaptedto support said die-element and a side arm integrally attached to saidtop portion, first pivot means connecting the butt end of said side armto the tool body at one side thereof, said support being swingable aboutsaid first pivot between a closed position in which said top portion isopposite said die member and an open position in which said top portionis offset laterally from the tool body, first spring means urging saidunitary die element support toward its open position, said top portionhaving a first latch surface thereon, a unitary releasable latch, secondpivot means connecting said latch to the tool body on the opposite sidethereof from said first pivot means, said latch having a second latchingsurface adapted to overlap and lock with the latch surface of said topportion when closed, and second spring means urging said latch intoengaging position with said second latch surface overlapping and lockingwith said first latch surface to hold said support in its predeterminedclosed position against the action of said first spring means, wherebysaid first spring means urges the die element support into tight lockingengagement with the latch in the closed position firmly holding the topportion of the die element support in a predetermined position oppositethe movable die member and said first spring means urges the die elementsupport into the fully open position when the latch is released.

3. In a tool for crimping electrical conductors, of the type having adie member movable on the tool body toward a die element supported lonthe tool head, the improvement whereby said die element can be latchedin a closed position and is automatically latched and locked inpredetermined position on the tool head opposite said die member when itis closed and automatically swings into the fully open position whenunlatched, said improvement comprising: a unitary top portion adapted tosupport said die element, said top portion having an upper fiat surface,first pivot means having its axis below said top portion and connectingsaid top portion to the tool body at one side therof, said top portionbeing swingable about said first pivot between a closed position inwhich said top portion is opposite said die member and an open position,first spring means urging said unitary top portion toward its openposition, said top portion having a first latch surface thereon, areleasable latch movably mounted on the opposite side of the tool bodyfrom said first pivot means, said latch having a second latching surfaceadapted to overlap and lock with the latch surface of said top portionwhen closed, and second spring means urging said latch into engagingposition with said second latch surface overlapping and locking withsaid first latch surface to hold said support in its predetermined closeposition against the action of said first spring means, whereby saidfirst spring means urges the top portion into tight locking engagementwith the latch in the closed posi- References Cited in the file of thispatent UNITED STATES PATENTS 1,547,565 Duda July 28, 1925 1,733,248Wilson et al Oct. 29, 1929 1,837,689 Sunde Dec. 22, 1931 2,113,087Jensen Apr. 5, 1938

